<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .welcome {
            height: 200px;
            line-height: 200px;
            text-align: center;
            font-size: 100px;
            background-color: #000;
            color: #fff;
        }

        a {
            /* 转化为行内块以设置宽高 */
            display: inline-block;
            width: 100%;

            text-align: center;
        }
    </style>
</head>
<body>
    <h1 class="welcome">
        来此作甚！
    </h1>
    <a href="../index.html"> &lt;&lt;润&gt;&gt; </a>
</body>
</html>